Showing papers on "Four-stroke engine published in 1995"

Free-piston engine

Abstract: A free-piston engine comprises a combustion part (1), a hydraulic control system (2), an energy consumption system and an engine control system. The combustion part comprises a combustion cylinder with at least one combustion piston (4). The hydraulic control system (2) comprises a hydraulic piston (24) which, together with a combustion piston (4), forms a piston assembly, and which has a first surface that, when under hydraulic pressure, exerts a force on the piston assembly (24) that is directed towards the combustion space (6) and a second surface, smaller than the first surface, that, when under hydraulic pressure, exerts a force on the piston assembly that is directed away from the combustion space. The hydraulic control system (2) further comprises a hydraulic cylinder (23) into which the hydraulic piston (9) sealingly fits, at least in the first position, a starting valve provided in a connecting channel between a first chamber, which is defined by the first surface and the hydraulic cylinder in the first position of the piston assembly, and a second chamber, which is defined by the second surface of the hydraulic piston (9) and the hydraulic cylinder (23), and a channel through which oil can flow from the pressure accumulator (14) to the second chamber, in which the first chamber can only be provided with oil in the first position via the starting valve. A return valve (19) is provided in the channel between the second chamber and the pressure accumulator (14).

Four cycle engine for watercraft

Abstract: A small, personal watercraft powered by a four cycle internal combustion engine. The engine is provided with a dry sump lubrication system for permitting the engine to be mounted low in the hull and this dry sump lubrication system includes a lubricant tank mounted within the hull separately from, but spaced closely to, the engine. Induction and exhaust systems are provided for the engine which include position responsive valves that close when the watercraft is inverted to preclude water from entering the combustion chamber through either the intake or the exhaust system. The induction system also includes an air inlet device that has its own position responsive check valve and which provides a centrifugal separator for separating water from the air inducted into the engine.

Supercharged internal combustion engine with capability for mechanical step-up drive of an exhaust gas turbocharger

Abstract: A supercharged internal combustion engine has an exhaust gas turbocharger which includes an exhaust gas turbine and a compressor. The exhaust gas turbine and the compressor are connected to a turbocharger shaft and an appliance for the transmission of power for the purpose of a mechanical step-up drive capability for the exhaust gas turbocharger arranged between the turbocharger shaft and the crankshaft of the internal combustion engine. The appliance includes at least one step-up gear and a controllable hydrodynamic coupling for torque transmission arranged between the crankshaft and the turbocharger shaft. In order to configure the internal combustion engine in a simple and compact constructional manner in such a way that a better increase in torque of the internal combustion engine can be achieved in the lower rotational speed range by the mechanical step-up drive of the exhaust gas turbocharger and to achieve substantially shorter response times during transient operation of the internal combustion engine, the hydrodynamic coupling can be locked up by a mechanical or electro-mechanical clutch and is arranged between the step-up gear and the crankshaft of the internal combustion engine.

Internal combustion engine with intake and exhaust camshaft phase shifting for cylinder deactivation

Abstract: A four-stroke cycle, multi-cylinder reciprocating internal combustion engine has a camshaft phaser or phasers for adjusting the timing of the intake and exhaust camshafts with respect to the rotational position of the crankshaft so that some of the cylinders of the engine may be deactivated such that the intake and exhaust valves for each deactivated cylinder open and close at points which are approximately symmetrical about a rotational position of the crankshaft at which the direction of motion of the pistons change.

Method and apparatus for starting an internal combustion engine

Abstract: A method and apparatus for starting an internal combustion engine, which comprises setting one piston of the internal combustion engine into a favorable starting position (X) and to supply a fuel/air mixture to the combustion space by means of a starting air source before the starting of the internal combustion engine.

Manifold and water trap system for marine engine

Abstract: A personal watercraft having a compact engine arrangement for driving a propulsion device such as a jet pump positioned to the rear of and on the underside of the watercraft. The engine is disposed so that its cylinder block is at an angle to a vertical plane, with the exhaust manifold being positioned on the underside of the cylinder bank. An expansion chamber device is provided at the rear end of the engine and at a height that is higher than the exhaust ports of the engine and the discharge of the exhaust system so as to provide a trap for precluding flow of water to the engine through the exhaust system. This positioning of the engine places its crankshaft in offset relationship to the drive shaft of the propulsion device, and a two-stage step-down transmission drives the drive shaft from the crankshaft.

Arrangement for regulating the engine braking effect of a combustion engine

Abstract: Arrangement for regulating the engine braking effect of a compressor (2) supercharged combustion engine (1) in a vehicle, which engine is equipped with an engine braking effect-increasing device, such as a compression brake device (10). The compressor is driveably connectable to the cam shaft of the engine via a transmission (13) with variable gearing in such a manner that the rotational speed of the compressor can be increased in relation to the engine rotation speed when the engine rotation speed decreases.

Cooling for gas turbine-two stroke piston compound engine

Abstract: A compound engine that includes a gas turbine unit and a piston unit wherein a portion of the cycle air for the piston unit is diverted through cooling passages to provide impingement cooling of several areas of the piston unit including the upper cylinder area, the outer and inner surfaces of the exhaust valve and other selected areas of the cylinder head; and there after, the diverted cycle air is reintroduced into the cycle.

Four cycle engine with two cycle compression braking system

Abstract: An on/off compression braking system is provided which when actuated controllably opens one inlet valve and one outlet valve in response to the actuation of the injector unit rocker arm and deactivates the exhaust valve rocker arm. This braking system thereby is useful on four cycle engines and is of a construction which eliminates elements of heretofore utilized compression braking systems and provides a four cycle engine with a two cycle compression braking system.

Fluid controlling system for an engine

Abstract: A fluid system of an engine which has an outwardly opening engine valve controls fluid delivery and removal from first and second cylinders for controlling the position of the engine valve and injection of fuel responsive to the position of the engine piston.

Apparatus to convert a four-stroke internal combustion engine to a two-stroke pneumatically powered engine

Abstract: An apparatus (10) to convert a four-stroke internal combustion engine to a two-stroke pneumatically powered engine. An air compressor (60) is driven using the rotation of the crankshaft (22) and compressed air is delivered through a supply line (74) to at least one holding tank (68). A supply line (76) delivers compressed air from the tank (68) through a regulator (20), which controls the pressure and volume, to the pneumatic distributor (24). A plurality of high pressure hoses (50) finally communicates the compressed air to the cylinders (86) of the engine (12) via the spark plug orifices (18). The pneumatic distributor (24) has a rotor (42) which opens gate valves (44) to supply compressed air to the cylinders (86) wherein the pistons (88) are at top dead center, making every downstroke a power stroke. The modified dual-lobed camshaft (80) operates the exhaust valves (84) so that every upstroke of a piston (88) is an exhaust stroke and exhaust freely escapes through the exhaust manifold (90).

Four-cycle engine

Abstract: An engine induction system having a check valve upstream of the intake port for precluding reverse flow A plenum device is communicated with the induction system downstream of the check valve for reducing inertial effects and improving charging efficiency The plenum device may be the crankcase chamber of the engine In that case crankcase ventilation may also be controlled and improved Crankcase supercharging may also be generated These features may be combined with variable valve timing to further improve engine performance

Valve duration control system for four-cycle engine

Abstract: A control system for a four-cycle internal combustion engine controls a cam drive mechanism for an intake valve such that a cam of the cam drive mechanism maintains a valve open duration of the intake valve at a short valve open duration in response to a shift from engine operation at low speed with low load to engine operation at low speed with high load, and the cam increases the valve open duration of the intake valve in response to a shift from engine operation at low speed with low load to engine operation at low speed with middle load that is higher than the low load but lower than the high load.

Operating mechanism for an engine brake valve of an internal combustion engine

Abstract: In an operating mechanism for an engine brake valve of an internal combustion engine which has fuel injectors mounted in the cylinder head to which pressurized fuel is delivered through high pressure fuel passages from a high pressure fuel injection pump, a hydraulic operating piston disposed in a hydraulic cylinder is operatively connected to the engine brake valve by way of a lever which is actuated by the hydraulic operating piston when fuel under pressure is supplied to the hydraulic cylinder and a hydraulic control valve is arranged in the high pressure fuel passages for selectively directing the high pressure fuel from the injection pump either to the injector for injection into the engine or to the hydraulic cylinder for opening the engine brake valve at the end of an engine compression stroke to discharge the compressed gas from the engine during engine braking operation.

Internal combustion engine utilizing pistons

Abstract: An internal combustion engine having a cylindrical outer case(s) defining a base compression cylinder(s) with an inner cylindrical cylinder(s) defining power cylinder(s) circumferentially spaced in the engine and each housing opposing intake and exhaust pistons. Inlet ports for supplying pressurized air to the pistons included a small percentage of base compression air stored in an accumulator at a pressure that is the highest pressure in the engine. Flex tubes judiciously mounted in the piston and attached at either end to the piston and piston ring for supplying air from the accumulator to a plurality of pockets formed in the piston ring to hydrostatically support the pistons and piston rings. The pistons power a rotary cam mounted on opposing ends of the engine and a cam follower system positions the pistons for the 2-cycle operation. A four bar linkage system operatively connected to the piston rod to minimize piston side loads. The passage between the power cylinder and base compression cylinder serves to admit heated air, indirectly heated during the combustion cycle, charges the power cylinder for improved efficiency. The absence of the block and the material used for the hot section of the engine are made from relatively light weight materials providing a significantly improved power to weight ratio.

Controller for four-stroke cycle internal-combustion engine

Abstract: A controller for a four-stroke cycle internal-combustion engine, which has a single sensor mounted on a crankshaft and employs a single sequence of position signal pulses corresponding to crank angles, achieves reduced cost and higher accuracy even for an engine with an odd number of cylinders. For each revolution of the crankshaft, a position signal pulse is issued from the sensor mounted on the crankshaft; the position signal pulse includes a reference position signal pulse in a number which is a multiple of N of the number of cylinders and a cylinder identifying signal pulse for a particular cylinder every time the crankshaft rotates. A control means includes a reference position signal generating section for identifying the reference position of each cylinder from the position signal pulse and for generating the reference position signal; a cylinder identifying section for identifying each cylinder from the position signal pulse and for generating a cylinder identifying signal; and a timing control section for generating a control signal for each cylinder in accordance with the reference position signal and the cylinder identifying signal. The control signal controls at least the ignition timing or the fuel injection timing of each cylinder.

Engine design for gasoline/diesel engines

Abstract: Improved designs for the internal combustion engine are disclosed. The first embodiment of the invention relates to a configuration in which the cylinder/piston assembly is inclined at an oblique angle relative to the center axis of rotation of the crankshaft and connected to the crankshaft with a curved or bow-shaped connecting rod. The second embodiment of the invention resides in an improved design for the combustion chamber. In this embodiment, the cylinder and piston have elliptical cross sections. This, combined with a concave cylinder head, provide for a ellipsoid shaped combustion chamber. In this chamber are mounted two spark plugs, positioned along the major axis of the ellipse defined by the cylinder cross section. This configuration then sets the stage for the phenomenon called "Dual opposite firing fronts."

Cam-controlled valve actuation for a 4-stroke/8-stroke internal combustion engine

Abstract: Two cams, which are arranged offset by 180 degrees on a camshaft, are assigned to an internal combustion engine lifting valve. The first cam acts directly on the lifting valve by way of a first rocker arm, the second cam acts on a second rocker arm, which can be coupled to the first rocker arm. If the two rocker arms are coupled to one another, both cams are operative and the lifting valve is actuated twice per camshaft revolution. If the rocker arms are separated from one another, only the first cam acts so that the lifting valve is actuated only once per camshaft revolution. If the camshaft rotates at one quarter of the crankshaft speed, the internal combustion engine is operated with rocker arms coupled to one another in 4-stroke operation and with rocker arms uncoupled in 8-stroke operation. The said 8-stroke operation is equivalent to an alternating cylinder shut-off.

In Cylinder Augmented Mixing Through Controlled Gaseous Jet Injection

Abstract: An investigation was performed on a direct injection diesel engine equipped with a gaseous injector to determine the effects of augmented mixing on emission characteristics. The gaseous injector introduced a jet of gas of particular composition in the cylinder during the latter portion of diesel combustion. This injector was controlled to inject the gas at specific engine timings and at various injection pressures. Engine experiments were done on a Labeco/Tacom single cylinder, direct injected, 1.2 liter, four stroke diesel engine. This engine was operated at 1,500 rpm at an equivalence ratio of 0.5 with simulated turbocharging. The fuel injection timing was changed for some cases to accommodate the gaseous injection. Exhaust particulate emissions were measured with a mini-dilution tunnel. All other emissions data were measured on a REGA 7000 Real-Time Exhaust Gas Analyzer Fourier Transform Infrared (FT-IR) system. Industrial grade nitrogen was injected at high pressures and at various crank angles to observe the nitrogen`s effects on emissions under different operating conditions. For an advanced diesel fuel injection timing, particulate emissions decreased to a minimum then increased as the auxiliary nitrogen injection occurred later in the combustion period. For retarded fuel timing, the effects of gas jets of different nitrogenmore » injection pressures were investigated. Again, a reduction in particulates was observed. Carbon dioxide was injected to investigate the effects of gas composition on soot oxidation. In this study, the carbon dioxide injection was detrimental to soot oxidation. Additionally, quantitative analyses were performed on the gaseous jet outside of the engine to show the relationship between momentum introduced by the jet and its effect on turbulent mixing and emissions.« less

A dual piston internal combustion engine

Abstract: An internal combustion engine (1) comprising at least two cylinders (4, 8) meeting to form a combustion space (12) therebetween, a first piston (3) adapted to reciprocate within the first cylinder (4) and a second piston (7) adapted to reciprocate within the second cylinder (8). The two pistons are drivably coupled via a chain drive connecting their respective crankshafts and synchronously move one with respect to the other such that the second piston moves at a frequency half of that of the first piston. An air/fuel mixture inlet aperture (14) as well as an exhaust aperture (15) are located in the wall of the second cylinder (8) and are opened or closed by the movement of the second piston (7). There is a further exhaust sealing valve (17) such as a rotary disc valve which opens or closes an exhaust port (16) connecting the exhaust aperture (15) to the outside (or exhaust system), the sealing valve (17) closing the exhaust port (16) so as to prevent exhaust gases from re-entering the combustion chamber (12) when the engine is in its intake stroke and when the exhaust aperture (15) is not covered by the second piston (7). The air/fuel mixture enters the combustion chamber (12) through a one-way valve (13), usually a reed valve.

Method and apparatus for sensing air flow into a cylinder of internal combustion engine and method and apparatus for controlling fuel of the internal combustion engine arranged to use the method and apparatus

Abstract: A method and an apparatus for sensing an air flow into a cylinder of an internal combustion engine are arranged to determine a number of revolutions of the engine, determine a pressure of an intake pipe of the engine, and calculate an air flow Qc into a cylinder of the engine, based on the number of revolutions and the pressure of the intake pipe by the linear expression of Qc=αP+β, in which α is a coefficient indicating a gradient of a linear expression and defined according to the number of revolutions, β is a coefficient indicating an offset value and defined according to the number of revolutions, and P is a pressure of the intake pipe. The method and the apparatus for controlling fuel of the internal combustion engine operate to generate a fuel flow signal according to the air flow into the cylinder determined by the above method and feed fuel to the internal combustion engine at a flow rate corresponding to a fuel flow signal.

Cylinder head for four stroke internal combustion engine

Abstract: Greater torque and power are realized in V-twin motorcycle engine with a cylinder head having a combustion chamber that incorporates two flow relief areas, one for each of the intake and exhaust ports, located on opposite right and left sides of the combustion chamber, and flow resist areas about the remaining portions of the respective port's periphery, obstructing gas flow into the flow resist areas. The foregoing arrangement defines a gas reversion path from the exhaust port that zig-zags through the chamber to the intake port, increasing the length of the path and reducing the adverse effect of reversion. A rectangular shaped intake port entrance and an accompanying rectangular shaped manifold passage provide for input of greater volume of combustible gas and a D-shaped exhaust port exit contribute to the effectiveness of the combination.

Cam carrier for an internal combustion engine

Abstract: A small four cycle internal combustion engine is disclosed having a cylinder head assembly which comprises a cylinder head cooperating with a cylinder block of the engine, and a rocker box connected to the cylinder head so as to define an air passage therebetween through which air may pass. The cylinder head has cooling fins projecting into the air passage between the cylinder head and the rocker box and aligned generally transversely to a line extending between the axes of the intake and exhaust valves. The air passage preferably extends between an intake port and an exhaust port of the engine, and above an exhaust gas recirculation port extending between the intake and exhaust ports. A pair of push rod tubes are integral with the rocker box and extend between the rocker box and a crankcase of the engine externally of the cylinder block. The engine of the present invention also includes a cam tower assembly comprising a base member and a pair of parallel shafts extending from the base member. One of the shafts functions as a camshaft and has a unitary cam gear and cam rotatably supported thereon. The other shaft is a follower shaft and has a pair of cam followers rotatably supported thereon.

Method for controlling the working cycle in an internal combustion engine and an engine for performing said method

Abstract: In-line engine with variable compression, comprising a cylinder receiving section which is tiltably mounted in the crankcase section (4) of the engine, in which the crankshaft is mounted by means of crankshaft bearings (90) arranged in the lower region of the crankcase section (4). The crankshaft bearings incorporate bearing caps (102) which constitute continuous stiffening transverse connecting elements between the lower lateral parts (104,106) of the crankcase section. These transversely connecting bearing caps rest at their outer end (108,110) against internal surface areas in the lower lateral parts (104,106) of the crankcase section on both sides of the engine. The bearing caps are securing in the crankcase section (4) not only by means of vertical crankshaft bearing screws (112,114) but also by means of screwed joints (166, 118, 120) which connect the lower lateral parts to the outer ends (108, 110) of the bearing caps.

Intake structure of four-cycle engine

Abstract: PURPOSE: To further effectively improve fuel consumption and to reduce exhaust gas by a method wherein an intake air return valve and an exhaust valve are driven through a common cam shaft and a cam phase angle varying device is arranged on the common cam shaft. CONSTITUTION: During partial load running at a low and middle speed rotation, the opening closing timing of an intake air return valve 19 is delayed togetherwith the opening closing timing of an exhaust valve 10 by a cam phase angle varying device 13 and even after an intake valve 8 is closed, the intake air return valve 19 is opened. Thus, an engine is reversed at an intake delay close mirror cycle and fuel consumption is improved through reduction of an intake pumping loss. Besides, since the opening closing timing of the exhaust valve 10 is simultaneously delayed, an overlap between the opening states of the intake valve 8 and the exhaust valve 10 is increased. Thereby, a part of burnt exhaust gas is returned to the cylinder again and internal partial EGR (exhaust gas recirculation) is effected, fuel consumption is further improved, and the generation of exhaust gas is also reduced. COPYRIGHT: (C)1996,JPO

EGR system for four=stroke engine

Abstract: The EGR system is esp. for a diesel engine. There is an additional mechanism, typically comprising an auxiliary hump (4) on the inlet valve cam (1). This opens one or more inlet valves (5) during the exhaust stroke, so that part of the exhaust is returned to the engine intake. Valve operation can be hydraulic, and controlled by an additional solenoid valve (13). The clearance of the inlet valve can be adjustable.

Modeling the effect of engine assembly mass on engine friction and vehicle fuel economy

Abstract: In this paper, an analytical model is developed to estimate the impact of reducing engine assembly mass (the term engine assembly refers to the moving components of the engine system, including crankshafts, valve train, pistons, and connecting rods) on engine friction and vehicle fuel economy. The relative changes in frictional mean effective pressure and fuel economy are proportional to the relative change in assembly mass. These changes increase rapidly as engine speed increases. Based on the model, a 25% reduction in engine assembly mass results in a 2% fuel economy improvement for a typical mid-size passenger car over the EPA Urban and Highway Driving Cycles.

Automotive i.c. engine with supplementary piston-and-cylinder energy accumulator

Abstract: A floating piston 11 is slidable in a cylinder bore 10 sealed at one end with automotive type piston rings. The piston 11 is preloaded against one closed end of the cylinder bore by a spring 12. The closed end against which the piston is preloaded is pierced so that a tube or airway 14 may communicate with the combustion chamber of an I.C. engine. The preload is made such that on the compression stroke of the engine the floating piston 11 will not move until the full compression pressure is reached. The subsequent pressure due to mixture burning moves the floating piston 11 against the spring 12 thus storing energy for use at a later portion of the engine stroke. The accumulator may be integral with the engine cylinder head or block or may be incorporated into the engine itself eg the working cylinder may contain two pistons spring loaded apart.

Method of piston internal combustion engine working and piston internal combustion engine

Abstract: This invention relates to engine-building and more particularly to a method of piston internal combustion engine working and may be used in stationary power-generating plants and in transport. A method of piston internal combustion engine working comprising the suction valve (1) opening into the cylinder (8) over-piston cavity, feeding the working medium into it before the suction valve (1) shutting off; further compressing and burning of the working medium with its further expansion and discharge of the worked-out gases. A detonating additive is added into the working medium, but the working medium expansion is preferably affected at its constant pressure and the over-piston cavity variable volume. The piston internal combustion engine comprises a rocker (5) of variable length which is provided by telescopic spring (24) of variable rigidity and hydrocylinder (13) and compensator (4) which is provided by a telescopic spring (28) of variable rigidity and hydrocylinder (31). A rocker (5) of variable length provides fuel burning at the constant pressure of the working medium and variable volume of the over-piston cavity. Compensator (4) provides automatical adjusting of the given compression pressure rate.

Rotary internal combustion engine

Abstract: not available for EP0775255Abstract of corresponding document: US5303679This engine includes an engine block rotatably mounted on a support and including a central chamber communicating with outwardly protruding radial piston chambers closed by cylinder heads. A crank shaft is rotatably mounted in the engine block parallel to the rotation axis of the latter and radially offset therefrom. A drive train couples the engine block with the crank shaft for causing rotation of the two in the same direction and at equal rotational speed. A piston is reciprocable in each piston chamber and all the pistons are linked by connecting rods to the crank shaft at connecting points which are angularly advanced in the direction of rotation of the engine block relative to the longitudinal axes of the piston chambers. It follows that the combustion stroke is effected while the connecting rods exert a maximal torque on the crank shaft.